In this paper, a novel SPME mode, PDMS-coated solid glass microspheres （SGMs）, were prepared by sol-gel method. Using homemade thermal desorption unit coupled with CGC-FID, six PAHs as model analytes, the performanc...In this paper, a novel SPME mode, PDMS-coated solid glass microspheres （SGMs）, were prepared by sol-gel method. Using homemade thermal desorption unit coupled with CGC-FID, six PAHs as model analytes, the performance of the new mode was characterized. The new extractive phase exhibited high thermal stability and satisfactory extraction capability. The detection limits were 0.01-0.045 ng/mL, and the linearity was from 0.5 ng/mL to 96 ng/mL. The R.S.D.s of repeatability for retention time and peak area were all within 0.074% and 6.7%, respectively. The recoveries of the PAHs were 78-127% from the samples taken from river water.展开更多
The discharge of the antibiotic wastewater has increased dramatically in our country with the development of medical science and wide application of antibiotic,resulting in serious harm to human body and ecological en...The discharge of the antibiotic wastewater has increased dramatically in our country with the development of medical science and wide application of antibiotic,resulting in serious harm to human body and ecological environment.In this work,ciprofloxacin(CIP)was selected as one of typical antibiotics and heterogeneous Fenton-like catalysts were prepared for the treatment of ciprofloxacin wastewater.The sodium alginate(SA)gel microspheres catalysts were prepared by polymerization method using double metal ions of Fe^(3+)and Mn^(2+)as cross-linking agents.Preparation conditions such as metal ions concentration,mass fraction of SA,polymerization temperature and dual-metal ions as crosslinking agent were optimized.Moreover,the effects of operating conditions such as initial concentration of CIP,pH value and catalyst dosage on CIP removal were studied.The kinetic equation showed that the effect of the initial concentration of CIP on the degradation rate was in line with second-order kinetics,and the effects of catalyst dosage and pH value on the degradation rate of CIP were in line with first-order kinetics.The SA gel microspheres catalysts prepared by dual-metal ions exhibited a high CIP removal and showed a good reusability after six recycles.The SA gel microspheres catalysts with an easy recovery performance provided an economical and efficient method for the removal of antibiotics in the future.展开更多
Direct electrochemistry and electrocatalysis of horseradish peroxidase（HRP） were achieved by entrapping the enzyme between CaCO3 microspheres and gold nanoparticles through forming sandwich configuration （CaCO3-HRP...Direct electrochemistry and electrocatalysis of horseradish peroxidase（HRP） were achieved by entrapping the enzyme between CaCO3 microspheres and gold nanoparticles through forming sandwich configuration （CaCO3-HRP-AuNPs）. Polyanion, poly（styrene sulfonate）（PSS）, was hybrid with CaCO3 microspheres to increase the surface negative charges for binding with HRP through electrostatic interaction. After the bioconjugate CaCO3 PSS-HRP was entrapped in chitosan based sol-gel（CS-GPTMS） film, HRP was encapsulated by in situ formation of an outer layer of AuNPs through electrochemical reduction of HAuCl4. The composite film containing AuNPs, CaCO3-PSS-HRP bioconjugates and CS-GPTMS can provide favorable microenvironment for HRP to perform direct electron transfer at glassy carbon electrode（GCE）. HRP retained its bioelectrocatalytic activity and lead to sensitive and fast amperometric response for the determination of H2O2. H2O2 could be detected in a very wide linear range from 5.0×10-6 mol/L to 7.1×10-2 mol/L. The sandwich configuration of CaCO3-biomolecules-AuNPs could serve as a versatile platform for enzyme immobilization and biosensing.展开更多
Spherical porous silica microparticles were synthesized by a sol-gel process in the presence of porous CaCO3 particles, followed by removal of the carbonate templates. The resulting silica particles had very high poro...Spherical porous silica microparticles were synthesized by a sol-gel process in the presence of porous CaCO3 particles, followed by removal of the carbonate templates. The resulting silica particles had very high porosity and wide pore size distribution, whose surface area and pore volume reached up to 367.3 m2/g and 0.72 mL/g, re- spectively. With a larger amount of the tetraethyl orthosilicate used, hollow silica microspheres were further obtained. Characterization was made to confirm the chemical and physical structures and purity of the silica microspheres. Spontaneous deposition of tetramethyl rhodamine isothiocyanate labeled dextran into the microspheres was also ob- served due to the charge attraction.展开更多
Sucrose ester( SE) was fixed on surface of poly( ethylene terephthalate)( PET) fibers to improve surface activity. Chitosan( CS) was used to graft onto pretreated PET fibers by sol-gel method. The transformations of s...Sucrose ester( SE) was fixed on surface of poly( ethylene terephthalate)( PET) fibers to improve surface activity. Chitosan( CS) was used to graft onto pretreated PET fibers by sol-gel method. The transformations of surface chemical structure,microcosmic morphology and thermodynamic property were investigated by Fourier transform infrared spectroscopy( FTIR),X-ray photoelectron spectroscopy( XPS), scanning electron microscope( SEM), X-ray diffraction technique( XRD), and thermo gravimetric analysis( TGA),respectively. The wettability and antistatic property of PET fiber were significantly improved after modification by SE and CS.展开更多
Magnetic alumina composite microspheres with γ-Fe 2 O 3 core/Al 2 O 3 shell structure were prepared by the oil column method. A dense silica layer was deposited on the surface of γ-Fe 2 O 3 particles （denoted as γ...Magnetic alumina composite microspheres with γ-Fe 2 O 3 core/Al 2 O 3 shell structure were prepared by the oil column method. A dense silica layer was deposited on the surface of γ-Fe 2 O 3 particles （denoted as γ-Fe 2 O 3 /SiO 2 ） with a desired thickness to protect the iron oxide core against acidic or high temperature conditions. γ-Fe 2 O 3 /SiO 2 /Al 2 O 3 particles with about 85 wt% Al 2 O 3 were obtained and showed to be suitable for practical applications as a magnetic catalyst or catalyst support due to their magnetic properties and pore structure. The products were characterized with scanning electron microscope （SEM） and transmission electron microscope （TEM）, nitrogen adsorption-desorption, and vibrating sample magnetometer （VSM）. The specific surface area and pore volume of the γ-Fe 2 O 3 /SiO 2 /Al 2 O 3 composite microspheres calcined at 500 ？ C were 200 m 2 /g and 0.77 cm 3 /g, respectively.展开更多
文摘In this paper, a novel SPME mode, PDMS-coated solid glass microspheres （SGMs）, were prepared by sol-gel method. Using homemade thermal desorption unit coupled with CGC-FID, six PAHs as model analytes, the performance of the new mode was characterized. The new extractive phase exhibited high thermal stability and satisfactory extraction capability. The detection limits were 0.01-0.045 ng/mL, and the linearity was from 0.5 ng/mL to 96 ng/mL. The R.S.D.s of repeatability for retention time and peak area were all within 0.074% and 6.7%, respectively. The recoveries of the PAHs were 78-127% from the samples taken from river water.
基金supported by the National Natural Science Foundation of China(22125802 and 22108012)Natural Science Foundation of Beijing Municipality(2222017)Fundamental Research Funds for the Central Universities(BUCTRC-202109)。
文摘The discharge of the antibiotic wastewater has increased dramatically in our country with the development of medical science and wide application of antibiotic,resulting in serious harm to human body and ecological environment.In this work,ciprofloxacin(CIP)was selected as one of typical antibiotics and heterogeneous Fenton-like catalysts were prepared for the treatment of ciprofloxacin wastewater.The sodium alginate(SA)gel microspheres catalysts were prepared by polymerization method using double metal ions of Fe^(3+)and Mn^(2+)as cross-linking agents.Preparation conditions such as metal ions concentration,mass fraction of SA,polymerization temperature and dual-metal ions as crosslinking agent were optimized.Moreover,the effects of operating conditions such as initial concentration of CIP,pH value and catalyst dosage on CIP removal were studied.The kinetic equation showed that the effect of the initial concentration of CIP on the degradation rate was in line with second-order kinetics,and the effects of catalyst dosage and pH value on the degradation rate of CIP were in line with first-order kinetics.The SA gel microspheres catalysts prepared by dual-metal ions exhibited a high CIP removal and showed a good reusability after six recycles.The SA gel microspheres catalysts with an easy recovery performance provided an economical and efficient method for the removal of antibiotics in the future.
基金Supported by the National Natural Science Foundation of China(Nos.20775039, 20602009)the Natural Science Foundation of Shandong Province of China(No.ZR2009BM031)+3 种基金the Public Welfare Project of Marine Science Research, China(Nos. 200705011, 200805039)the Scientific Research Fund of the First Institute of Oceanographythe State Oceanic Administration of China(No.2010T04)the Science and Technology Project of Shandong Company of China National Tobacco Corpora-tion(No.KN172)
文摘Direct electrochemistry and electrocatalysis of horseradish peroxidase（HRP） were achieved by entrapping the enzyme between CaCO3 microspheres and gold nanoparticles through forming sandwich configuration （CaCO3-HRP-AuNPs）. Polyanion, poly（styrene sulfonate）（PSS）, was hybrid with CaCO3 microspheres to increase the surface negative charges for binding with HRP through electrostatic interaction. After the bioconjugate CaCO3 PSS-HRP was entrapped in chitosan based sol-gel（CS-GPTMS） film, HRP was encapsulated by in situ formation of an outer layer of AuNPs through electrochemical reduction of HAuCl4. The composite film containing AuNPs, CaCO3-PSS-HRP bioconjugates and CS-GPTMS can provide favorable microenvironment for HRP to perform direct electron transfer at glassy carbon electrode（GCE）. HRP retained its bioelectrocatalytic activity and lead to sensitive and fast amperometric response for the determination of H2O2. H2O2 could be detected in a very wide linear range from 5.0×10-6 mol/L to 7.1×10-2 mol/L. The sandwich configuration of CaCO3-biomolecules-AuNPs could serve as a versatile platform for enzyme immobilization and biosensing.
基金Supported by the National Natural Science Foundation of China(No.50873087)the Natural Science Foundation of Zhejiang Province,China(No.Z4090177)the Project of Ministry of Science and Technology of China for the Indo-China Cooperation(No.2010DFA51510)
文摘Spherical porous silica microparticles were synthesized by a sol-gel process in the presence of porous CaCO3 particles, followed by removal of the carbonate templates. The resulting silica particles had very high porosity and wide pore size distribution, whose surface area and pore volume reached up to 367.3 m2/g and 0.72 mL/g, re- spectively. With a larger amount of the tetraethyl orthosilicate used, hollow silica microspheres were further obtained. Characterization was made to confirm the chemical and physical structures and purity of the silica microspheres. Spontaneous deposition of tetramethyl rhodamine isothiocyanate labeled dextran into the microspheres was also ob- served due to the charge attraction.
文摘Sucrose ester( SE) was fixed on surface of poly( ethylene terephthalate)( PET) fibers to improve surface activity. Chitosan( CS) was used to graft onto pretreated PET fibers by sol-gel method. The transformations of surface chemical structure,microcosmic morphology and thermodynamic property were investigated by Fourier transform infrared spectroscopy( FTIR),X-ray photoelectron spectroscopy( XPS), scanning electron microscope( SEM), X-ray diffraction technique( XRD), and thermo gravimetric analysis( TGA),respectively. The wettability and antistatic property of PET fiber were significantly improved after modification by SE and CS.
基金supported by the State Key Basic Research Program of PRC (2006CB202505)the National Natural Science Foundation of China (20806093)
文摘Magnetic alumina composite microspheres with γ-Fe 2 O 3 core/Al 2 O 3 shell structure were prepared by the oil column method. A dense silica layer was deposited on the surface of γ-Fe 2 O 3 particles （denoted as γ-Fe 2 O 3 /SiO 2 ） with a desired thickness to protect the iron oxide core against acidic or high temperature conditions. γ-Fe 2 O 3 /SiO 2 /Al 2 O 3 particles with about 85 wt% Al 2 O 3 were obtained and showed to be suitable for practical applications as a magnetic catalyst or catalyst support due to their magnetic properties and pore structure. The products were characterized with scanning electron microscope （SEM） and transmission electron microscope （TEM）, nitrogen adsorption-desorption, and vibrating sample magnetometer （VSM）. The specific surface area and pore volume of the γ-Fe 2 O 3 /SiO 2 /Al 2 O 3 composite microspheres calcined at 500 ？ C were 200 m 2 /g and 0.77 cm 3 /g, respectively.
